This invention relates to drop dispensing containers and, in particular, to a drop forming tip for such liquid dispensing containers.
Various drop dispensing containers have been used and are known in the art. Such containers include tips configured to form and release drops of liquid such as, for example, liquid medication into the eyes of a user, or the like. Despite the availability and use of these various containers, liquid medication often cannot be dispensed without dripping, thereby generating expensive waste. Thus, there remains a need for an improved tip for such containers which tip can reliably dispense substantially uniform drops without dripping. The present invention satisfies this need.
A liquid drop dispensing container is provided with a dispensing tip that includes a hollow stem which defines a liquid passageway. An interior partition wall within the stem divides the liquid passageway into an upstream chamber and a downstream chamber. The upstream chamber communicates with the interior of the container, and the downstream chamber terminates in a liquid drop outlet. A liquid passage is provided in the interior partition wall and provides flow communication between the upstream chamber and the downstream chamber. A unitary head portion extends into the downstream chamber from the partition wall and defines a rounded liquid impingement surface. Liquid passing from the upstream chamber into the downstream chamber contacts the rounded impingement surface and passes dropwise through the liquid drop outlet.
In a preferred embodiment, the liquid passage is positioned off-center and spaced from the liquid impingement surface. The interior partition wall includes opposed and outwardly diverging first and second faces which partially define the downstream chamber. The liquid passage terminates in an aperture located in the first face, and the unitary head portion extends outwardly into the downstream chamber from the second face.
The present invention also contemplates an apparatus for molding the liquid drop dispensing tip for a container. The apparatus includes a first mold insert for forming one side of the interior partition wall as well as the downstream chamber within the tip, and a second mold insert for forming the other side of the partition wall as well as the upstream chamber within the tip. The second mold insert includes an elongated pin for forming the liquid passage in the partition wall.
The distal end portion of the first mold insert includes first and second inclined faces which intersect along an edge. A cavity in the first inclined face of the first mold insert is complementary to an forms the rounded impingement surface which extends from the partition wall into downstream chamber.
The second mold insert includes a pin which extends longitudinally therethrough. The distal tip of the pin projects beyond the second mold insert. When both mold inserts are positioned against one another during the tip molding process, the distal tip of the pin abuts one face of the first mold insert and forms the liquid passage between the upstream and downstream chambers as molding material is injected into the mold. The mold inserts are urged against one another during molding.
Other features and advantages of the present invention will become readily apparent from the following detailed description, the appended drawings, and the accompanying claims.